Problems in the implementation of a combined continuous-discrete simulation language

GSL (Generalized Simulation Language) is a combined continuous-discrete simulation language which permits the simulation of either type of system or a combin ation of the two. The combination leads to powerful new capabilities, including creating and dynamically controlling multiple instances of continuous systems, extensive control over execution and events, and extensive interprocess communication. These capabil ities in turn lead to implementation problems, primarily in the areas of scheduling of multiple continuous simulation blocks, control of interaction between simulation blocks, coordination with discrete blocks, and storage allocation. The resolution of these problems in the GSL implementation is described along with experience with typical problems.